Microsoft is stepping up its Genuine Advantage program, and requiring a "piracy check" for all customers who want to download patches — excepting security updates — for Windows XP.

This is a great strategy… for Microsoft's competition. I don't have any figures on the number of "pirated" copies of Windows XP, but I'd be willing to bet that at least 25 percent of Windows XP users in the U.S. are using copies of XP that they don't have a legitimate license for.

Microsoft is at the point where it's unlikely that it will increase its already mammoth market share — so they've reached the conclusion that they need to start shaking down the non-paying or under-paying users. There's nothing wrong with that, really. As I've said before, I do think that people should pay for Windows if they're going to use it — and if Microsoft's licensing policies are too draconian for your taste, use an OS that doesn't require the purchase of a license for each PC. Just because everyone wants 'free' Windows, doesn't mean they can have it.

But it's probably not going to endear Microsoft to the many users who are using illicit copies of Windows, for whatever reasons. The company may be successful in forcing some users to pay for their copies of Windows, but it will also anger some of its users — who may not be paying Microsoft for Windows, but they do contribute to Microsoft's dominant position. Some of those users will eventually decide to look elsewhere.

Enforcing Genuine Advantage isn't going to convert Windows users to Linux users in droves, but I think it is going to annoy a number of Windows users to the point that some consider switching to Linux, Mac OS X or another OS. Even if the shift is only a few percentage points, that's a huge boost for Mac OS X or Linux.

Microsoft's new policy should also serve as a wake-up call to users who use Microsoft Windows, Microsoft Office and other proprietary packages without paying for a legitimate license. Authentication schemes will become more rigid and strictly enforced over time. Eventually, users are going to need to choose between paying for a legitimate copy, or using software that doesn't come with a license fee.